..........Tuning the mm x450.........new ? post 59

[Frank]

Canadian regulations call for pipe tape meeting CSA/ULC-S642 (Yellow Gas Line Thread Seal Tape with PTFE). It's thicker and denser than the standard white Teflon tape.

[flatblack]

Im wondering what the us standards are, it came with white tape on all the fitings and it was a gotpropane kit from 5 years ago. I would imagine white would be ok here if it came with the tape.

[storm]

I would doubt it as the white tape cannot hold the pressure of liquid LPG. You can get a sealing compound, it dries hard and seals the joint making it near impossible to remove anything joined with it, and even it it yellow (in Australia at least).

[franz]

The fitting at the mixer is not under pressure, actually a slight vacuum. Any thread sealer is sufficient. I am not a fan of Teflon tape. Every leak I have ever had was with tape, none with the liquid paste sealer. NFPA 58 allows any "approved thread sealant applied to the male threads).

I havent checked my Canadian codes recently, dont they allow a liquid teflon paste or a heavy paste (Rectorseal?)

[storm]

The fitting at the mixer is not under pressure, actually a slight vacuum. Any thread sealer is sufficient. I am not a fan of Teflon tape. Every leak I have ever had was with tape, none with the liquid paste sealer. NFPA 58 allows any "approved thread sealant applied to the male threads).

I havent checked my Canadian codes recently, dont they allow a liquid teflon paste or a heavy paste (Rectorseal?)

The fitting in this post, which is what I thought we were discussing but I may be wrong (again, lol), is not a gas fitting it is a liquid fitting.

[flatblack]

This sealant(rector seal)(white and yellow) is it good to use on all the joints of the system..? Lowes has it for 3.25 a tube, ill buy it and use it on my whole system when i move it.

[franz]

This shows the difference between regulatory jurisdictions. Where I live, I work with a regulatory authority. I do work with international clients and many of them have different regulations in effect. I flat missed that thread about the liquid fitting. The US allows the "approved thread sealant" in any fitting in liquid or gas service. One should always verify with their regional regulatory authorities before performing any work.

Some jurisdictions do not allow the user to perform any work on liquid systems, they must be licensed, or it must be inspected prior to pressurizing.

Franz

[flatblack]

I just ordered a aem wideband air fuel guage with heated o2 sensor, the narrow band guage and one wire o2 sensor sucked. Whats the ratio reading the guage should read from point to point thats still ok for it to run..? (example the pic shows 14.1) Its a digital guage that reads with the lights for the mixture and the number for the exact reading. Is there a certain # it should be under load..?.

[flatblack]

I got the guage and the timing all done, the fuel guage goes form 13.3-14.5. I cant lean it out any more than that, the timing i set at 6 degrees, still needs more tho i have a ping under load if your easy on it then give it some more pedal it gets worse. Are my air/fuel readings ok..? I cant get above my 14.5, the screw is all in.

[franz]

Stoich for propane is 15.5:1. A rich fuel mixture can lead to pinging. Check the three metering rod heights (the retaining studs). they should be uniform at about .826" on page 52 of my guide.

[flatblack]

I have the initial set at 8 degrees btdc and the total at 33. Seems to run real good, ill check the metering rod heigths tonite at work when i have a dial caliper on hand. since i still do get mid 13s at idle and mid 14s under load. A little leaner should make it run better im thinking.

[Steptoe]

I would doubt it as the white tape cannot hold the pressure of liquid LPG

My install has had white celon tape on all threads for 30 yrs...in that time tanks have been re tested several times (regulations) car rebuilt etc....and the whole system has to be checked for certcation every 12 months by a registared certifier....never had a leak.
The big issue with brass fittings, taps etc is over torqueing, didtoryion of threads tapers etc...not the tape.
The only places I dont use tape is water plumbing fittings ....use plumbers hemp....and head bolts, locktite plumbers sealant

I have the initial set at 8 degrees btdc and the total at 33.

That with VA not attached?
Not many dizzys have 25 deg of cent in them unless modified...
you sure thats right?
And 33 deg @ what rpms?... close to highway speeds?

[flatblack]

Not a dizzy and not va advance. I have a mallory unilite with mechanical advance, it has 25 degrees of advance in by 3,000 all built in. They make a spring kit for that to change if needed, i thought about changing it to a dizzy tho..... So i set the initial at 8 and the advance is at 25 giving me 33 total, the higher my initial the higher my total would be. I was going to try 10,12 or 14 but i wasnt sure about the total being that high, since 14 would be 39 advanced. With my borowed snap-on digital light it reads the rpms and the advance is all there at 3,000.

Ill check the rod heigth tonight and adjust if needed, the setting makes it a little rich at idle and under load. Hopefully that will get me where needed....thanks guys, ill let you know what i come up with.

[Steptoe]

Cool...yep seems all in the ball park..and you have you head around this stuff..along the same lines I modded my GM HEI ..I add approx another 5 or 6 degs in the VA, dropping out on light loads up hills.
rather than changing intial increasing or decreasing the springs?? watch you dont get bouncing springs at idle tho.
Have found there is a piont withing a couple degrees, retarding the power and economy drops off fast...just above this seems opitum...going higher adds nothing other than 'sounds more grunty' NOx increase etc.

[flatblack]

The rods measure .837 .838 and .839....thats an average of .012 longer than the .826, to make this leaner what way should i move these..?...im thinking they should be shorter, does that sound right..?